Abstract

After fabric relaxation, there is a reduction in wale and course density due to a reduction in loop length and this actually will affect the fabric properties. Then, it is useful to find a relation between loop length and courses and wales per unit length as well as the yarn thickness because wales and courses per unit length can be easily measured at any state while it is difficult to measure the loop length in the knitted fabrics. Therefore, it is required to find an equation, through which the value of loop length can be easily calculated from the measured values of courses and wales per unit length at any state after the knitting process. In this work estimated equations to calculate the knitted loop length for open to normal structure and for normal to compact structure are developed. By comparing the value of the loop length predicted from this work with the other mentioned models, it was found that the calculated values are very near to the L value of the case study, so the developed equations are acceptable. The tightness factor and the porosity of single jersey fabrics were also calculated theoretically.

Abstract

Collapsible unsaturated soils are characterized by a low-density composition and exhibit sudden settlement after wetting while maintaining in-situ stress levels. This issue is effectively mitigated by compaction, a simple and economical technique that improves the soil properties and geotechnical behaviour. In this study, the collapsible behaviour of a compacted sandy laterite soil is analysed, focusing on the influence of relative compaction, water content, initial suction and inundation stress. The primary aim is to analyse the effect of initial compaction conditions on collapse potential. Conventional and suction-controlled oedometer tests were conducted on soils from Ilha Solteira, São Paulo, Brazil, where there is a large amount of geotechnical data available. The laboratory data reveal that collapse deformations of compacted soil depend on relative compaction, initial water content, soil suction, and inundation stress. Poorly compacted soils exhibit greater susceptibility to collapse when wetted, and the magnitude of collapse potential varies with water content. Additionally, this study shows the influence of initial suction on collapsibility of less compacted soils. The laboratory results highlighted the importance of considering suction and inundation stress in understanding the collapsible behaviour of compacted soil, whereas traditional empirical methods often emphasize low density and water content as primary factors predisposing soils to collapse.